Ignition system



Nov. 3, 1936. H. B. HOLTHOUSE 2,059,237

- IGNITION SYSTEM Original Filed April 22, 1929 2 Sheets-Sheet 1 Nev. 3,1936.- H. B. HOLTHOUSE 2,059,237

- v mumxou SYSTEM 1 Original Filed April 22, 1929 2 Sheets-Sheet 2Patented Nov. 3, 1936 Q umrsn STAT-ES IGNITION SYSTEM Harry BarnardHolthouse, Chicago, Ill.

.Application April 22, 1929, Serial No. 856,963 Renewed January 3, 193339 Claims.

My invention relates to ignition systems, and particularly to anignition system employing the principles set out in my prior Patent No.1,710,541, issued April 23, 1929, on an application which was co-pendingwith this one. I

The object of the invention is the provisionof a system which willdevelop a spark of such characteristics as to ignite a combustiblemixture under pressure more .readily and efllciently 20 veryadvantageous in an ignition system. Ap-

parently there are two reasons for this, one being that because-thecurrent oscillates back and forth until it dies down, the spark lastslonger;

the other reason being that ozone is formed just before or during thehigh frequency sparking. Ozone apparently has a very desirable effect infacilitating ignition.

A further and important object of my inven tion is the provision of animproved timer mechanism for use with a system of this character.

Another object is the development of a new piece of apparatus applicablefor use with high frequency oscillating ignition systems, which piece ofapparatus is of utility as a spark gap,

timer, commutator, or the like, or timer and spark gap, as required inthe use of the circuit. This piece of apparatus comprises a rotarycontact or electrode, and a stationary contact or electrode ridingeither directly on and in contact with the'rotary contact or slightlyspaced therefrom, depending on its use. when the device is .used as atimer, the rotary contact has a depression in its surface which passesunder the stationary contact to interrupt the flow of current betweenthem, the stationary contact being held removed from the rotary contactat this time by insulated guards at rotary contact.

This construction 'has an advantage over previous rotary types of timersin that the use of 1a depression instead of an insulating segmentprevents the formation of a thin conductive film beyond the contact,along which film the other 55 contact would wipe. Such a conductive filmex- The use of a high frequency oscillating circuit is the sides of thevtending between the contacts when they should be separated hasheretofore made the interruption 01' the current less sharp and suddenthan the interruption secured by the present invention. O! course, theordinary spring contact a type of timer cannot compare with this in thesharpness ofcurrent interruption.

When the device is used as aspark gap, the same stationary contact mayform a sparking electrode when it is spaced from the rotating con- 1tact by the depression mentioned. or a separate electrode constantlyseparated from the rotating contact or electrode may be provided. Ineither case this invention. has the advantage of forming a spark gap,the length of which is absolutely 15 accurate, while the eiliciency, ofthe spark gap is assured by constant renewal of the air therein. I IFurthermore, the depression, when shaped as illustrated, will accuratelyreduce the length of the gap during each sparking period. A reduced 20gap'will permit a spark to be initiated or continued with a lowervoltage.

When the same contact is used, both for timing and sparking, it has anadditional distinct advantage over spring contacts in that with this 5device the gap may be extremely small without interfering with the timeraction, while spring. contacts can hardly be separated quickly withoutforming a fairly long gap. I

Other objects and features of the invention 30 will be apparent from aconsideration of the detailed description taken in connection with theaccompanying drawings, in which:

Fig. 1 is a perspective view showing one e'mbodiment of a novel piece ofapparatus con- 35 structed in accordance with the present invention. i

Fig. 2 tea longitudinal sectional view through the apparatus at Fig. 1.

Fig. 3 is a sectional 3,-3 of Fig. 2. I

Fig. 4 shows another arrangement which can I be employed with the timersparking apparatus.

Fig. 5 is a circuit designed for a particular use and embodying thefeatures 01' the present invention.

Fig. 6 is a modified circuit arrangement in which the timer apparatus isslightly differently I arransed view taken along the line use with theroller, these modifications being par- 55 Fig. 7 is still another andsimplified circuit ployed.

As previously stated, the application oi high frequency oscillatingcircuits to ignition systems is one oi the important features oi thisinven-- tion. To get the best results from such high frequency ignition,certain timing and sparking apparatus has been developed, and thereforebe-- fore describing the circuit arrangements shown in Figs. 5 to 7, Iwill describe the apparatus of Figs. 1 to 4, which is of greatimportance in the practical working out of the systems oi. Figs. 5 to"7.

The structure of Figs. l to may i at be considered simply a to niudbreit eyice or timer as ii. it had merely 1e :iunctiori a malre and-breaktimer of the conventional ignition systems now used in automobiles. Asis well known, such timers first close the circuit so that a currentwill flow therein and then. open the circuit to interrupt the current.The purpose of such timers is to build up, at the proper time and bymeans of the other parts of the system, a high induced voltage either inthe circuit in which the contacts of the timer are connected or in asecondary circuit. A. very sudden break in the current is desirablesince the more sudden the break is, the higher the voltage will be.

In the structure of 1 to 3, the timer contacts which make and break thecurrent are the contact H) and the rotary contact H which ro-- tateswith its circumferential surface in sliding engagement with contact l0,except when separated therefrom by the depression lid in the surface ofthe rotary contact i 1. Except for the depression I la the rotarycontact H is circular, as shown best in Fig. 3. On the two sides of therotary contact II are secured ring-shaped side plates I2 and 13, whichmay be insulated by mica sheets I6 and I].

The rotary contact H, together with the side plates l2 and 13, comprisesa roller A which is mounted on a shaft IS in any suitable way, as bynuts l9. When the roller is employed in an ignition or similar circuit,it becomes necessary to connect the rotary contact ii electrically inthe circuit. This may be done in any way known in the art, and forillustration 1 show a small slip ring 2! carried by the shaft 18 with asuit able type of brush 22 whereby the rotary contact 1 I may beconnected into the circuit through the shaft, slip ring and brush.

The roller A is driven by the shaft H3 in synchronism with the motor,and the depression I la is so positioned as to break the circuit when aspark in the engine is desired. As the shoulder llb passes out fromunder the contact Ill toward the position illustrated in Fig. 3, thecontacts In and II will thus be separated breaking the circuit throughthem. The depression Ha in under the contact l0, there is no adjacentsurface onto which the contact ID could wipe a conductive film from thecontact H.

In some high frequency ignition systems, such as those illustrated inFigs. 5 and 7, it is essential that a spark gap be provided, eitherbetween the timer contacts or in parallel with them. In the structureshown in Figs. 1 to 3, the depression Ila forms the spark gap betweencontact Ill and the rotary contact H. Thus, after the shoulder I lbpasses from under the contact l0, breaking the circuit, a spark may Jumpbetween the contact In and the bottom of the depression Ila. Since thecontact Hi rests on the side plates [2 ing portions of the roller.

.ticularly suitable when automatic tuning is cmand i3 which are rigidlysecured to th contact Ii, and since the depth and shape depression arefixed, it follows that the the spark gap formed by the depress .o. isvery exactly predetermined. t

In Fig. i I have shown a construction i similar to that in Figs. i to 3,except that contact H0 is utilized merely for inter u t the circuit, aseparate sparking electro being provided. This electrode 3a is com brushor spacer block N3 of insulating rial which rides on the peripheral iacroller l-l. The electrode Win15 preferably ed. lntothe spacer bloch i223so that i of its separation the rotary cont. be easily adjusted. Therotary concoc forms a rotary electrode which, toge electrode lillc,forms a spark "ti of which is accurately determined by th poo ion ofelectrode Milo in its spacer block H3. e i illustrated form thedepression lilo is deeper at its forward end liib than prcssion ilo, sothat the spark will not easily between contacts Hi. and ill with.portion i i ll) passes under contact I it. t.

As is clearly seen from Fig. 4, a circuit :3 closed by engagement ofthecontoct i the rotary contact ill during a part oi t 1 lution ofroller Hi. When the depression passes entirely under the contact Nil, oicurrent between the contact IN) and tary contact lll is interrupted. Atthis time spark will jump from the electrode i23c to the rotary contactor electrode Hi, the clap: ion lilb not yet having reached the positionof the electrode l23a.

I might mention briefly here further details oi mechanical constructionof the roller. The c ducting portion I l of the roller of course, modeof a currentmarrying material, i prefer the mechanical characteristicsto withstand tion, etc, to which it is subjected. The pl and i3 carry nocurrent, having solely tl tion of supporting brushes aw J iro u to.

during the sparking interval. make them of non-condo, the time oi? thepresent vii stantusc. I have tried many materiel.c "*1 5. far, my bestresults have been obtained witl'i a high grade of steel, which makes itnecessary to insulate these circular plates from the conduct To thispurpose, the mica sheets l5 and II are employed and, as 2 showsytheportion II is cut away to avoid all possible contact with the assemblingM. I

may employ an insulating material to surrourul the screws M, but I havefound that when using a high frequency current, I obtain the bestresults by leaving the open space shown.

In describing the circuits shown in Figs. ll, 8 and '7, it is probablybest to start with Fig. 7, since this is the simplest of the threecircuits. The coil MI is the coil of a magneto and as such is both a.source of power and an induction coil. Because this coil is assumed tobe a magneto coil, no other source of current is shown, since thevoltage would be generated in the coil 23! -by the magneto. It should beunderstood, however, that any other sources of current can be used, suchas those illustrated in my prior patent previously mentioned, theapplication for which was co-pending with this application.

the contact 2, this ,timer-sparker being perhaps the same asthatillustrated in Figs. 1 to 3.

When the contacts 2H! and 2| I are in contact, the coil 23I isshort-circuited so that a heavy current flows through said coil andthrough the said contacts during the period of excitation of the coil.As the rotary contact 2 rotates so that its depression passes under thecontact 2IIl, separating the contacts, the current flow through thesecontacts is interrupted, with the result that a high induced voltage isbuilt up in the coil 23I, and this voltage charges the condenser 239.The condenser 239 is connected'in series with a primary coil 234 of ahigh frequency transformer, and the two are connected across theconductors 232 and 233, thus beingconnected in a series circuit with thecoil 23I. It is the momentary flow of current in this circuit whichcharges the condenser. It will beobserved, however, that the coil 234and the condenser 233 are also in a series circuit with the contacts 2H3and 2H. The condenser discharges through this primary circuit with ahigh frequency oscillating current which, in flowing through the primarycoil 234, induces a corresponding potential in the secondary coil 23? oithe high frequency transformer. The coil 231 is also in a high frequencyoscillating circuit which includes the condenser 239 and a spark gap243, this gap being that formed by the contacts of a spark plug in theinternal combustion motor with which this ignition system is used. Thespark plug may be o e of several which are successively connectedthrough a distributor 5t diagrammatically illustrated. It is evidentfrom the circuit that as long as there is present in the wires 332 I and233 a voltage or current adequate to charge the condenser 233 and causean adequate sparking voltage, a spark will therefore continue to jumpacross the gap 283. A ground symbol is applied to conductor 233 toindicate that ground instead of a wire may be used for this conductor.

Fig. 5 illustrates a similar ignition system in which sparks areproduced simultaneously at the two spark plugs 43 and it which may be inan engine having two opposed cylinders firing simultaneously. In thissystem the primary oscillating circuit includes, besides condenser 33and contacts It and ii, two primary windings 3t and as, each of which isassociated with one of the secondary windings 3i and 38. Winding 37 isin a high frequency oscillating circuit including spark plug 53 andcondenser 39 connected through ground, and winding 33 is in a highfrequency oscillating circuit which is the same except that it includesspark plug 44 instead of spark plug 43. The timer including contacts i0and II is connected across conductors 32 and 33 across which are alsoconnected the condenser H and a coil 31 similar to coil 23I. Except forthe addition of condenser 4I, this circuit is similar in operation tothat of Fig. 7 just described, though producing two simultaneous sparksinstead of one. Con denser 4.I takes any of the charge developed by coil3i when its circuit is interrupted at I0 which the condenser 33 may notbe able to absorb at once, and hence the condenser 4I may act as areservoir for condenser 39. y

In Fig. 6 the rotary contact In isconnected to conductor I33 and contactIII) is merely a timing contact connected to conductor I32 through awire I48 and a manually controlled switch I43. A sparking contact I2 isalso provided, primary coil I34 and condenser I39 being connected acrossconductors I32 and I33 through this contact I23a and contact III. Asecond condenser MI is connected across'the conductors I32 and I33 towhich the magneto coil I3I is shunted across the primary transformercoil I34 and the condenser I39 to give improved performance undercertain conditions, though satisfactor'y results may be obtained withoutit. The secondary oscillating circuit, including secondary coll I3'I,condenser I39 and spark plug 143, is similar to that of Figi '7.

In the operation of this circuit when the switch I 49 is closed, asduring starting, the coil I3I. is first short-circuited by the contactsI I9 and ill to cause a heavy current to flow therethrough. When thesecontacts separate and interrupt the current, a high voltage charge isimpressed on the condensers HI and I33, which impress a highvoltage'across the spark gap formed by electrodes I230. and iii. Whenthis voltage is sufllciently high, the spark occurs and a high frequencycurrent flows through the primarycircuit including the primary coil I34of the high frequency transformer. This of course induces a highfrequency current in the secondary circuit including the secondary-coil531 of the transformer, the condenser I39and the spark plug I43 of themotor.

One of the principal utilities of my invention is the readiness withwhich it can be adapted for automatic timing, and in actual practicethis is the way in which I have employed it, especially the circuit ofFig. 6, with the best results. It is well known that in a magneto thevoltage rises and falls approximately in accordance with a sine wave. Itis also well known that the maximum voltage at the peaks of the wavesand there-- fore the voltage between zero and the peak of the wave,increases as the speed of the magneto increases, and since the speed ofthe magneto when it is used in the ignition system of a motor is ofcourse proportional to the speed of the engine,'it follows that thevoltage of the magneto increases as the motor speed increases.Nevertheless. the crest of the sine wave is always synchronized with apredetermined position of the engine.

The use of this speed-increased voltage of synchronizedsine wave form inautomatic timing was described in my prior patent previously men--tioned. I amable to arrange the spark gap so that at a given speed thevoltage at the crest oi the sine wave will be sufficient to cause aspark to jump across the gap and so generate the high frequencyoscillating current in the primary circuit which inductively generatesan oscillating current in the secondary circuit, causing a aspark tooccur at the points of the spark plug. As the engine speeds up, thevoltage necessary to jump the gap is reached at an earlier part of thesine wave, and therefore the timing of the spark is advanced. In otherwords, once the proper adjustment of .the gap is obtained, the spark isautomatically advanced or retarded in accordance with the motor speed,full automatic timing being obtained even with 'motor' cordance with'theabove description. Because of the fact that the switch I49 is open, theautomatic contact III! is inefiective and may be ignored. Thereforeinstead oi the apart: occur ring when the depression in the rotarycontact III passes under the contact ill], the spark will occur when thevoltage of the magneto coil iii, increasing according to its sine wavecharacter istic, reaches a suiilcient value to Jump the gap between therotary contact or electrode Hi and the stationary electrode I2Ila. Asthe engine speeds up so that this voltage is reached earlier in the sinewave, the spark is advanced, and conversely, as the engine slows down,the spark is retarded.

It is in connection with such systems using automatic timing that thetype oi apparatus shown in Figs. Band 9 is of particular utility.Referring to Fig. 8 first, the roller 3H is formed with no depressionwhatsoever, and a spec 5 block or brush iii of insulating material, suchas fiber, rides constantly on the periphery oi? the roller. An electrode52 is sccureui by u. screw 53 to the side of the brush in such a war asto clear the roller and leave a narrow gap of so 'i clearance as topermit sparking between this electrode and the roller. This electrodecan be adjusted to have the proper clearance anti is used in automatictiming. In actual fact, I employ this installation where the roller 3Hthe fi wheel of a motor and the spacing block on the periphery of thefly-wheel, and t is between the fly-wheel and the elect: rled by thespacing block. With a gell tern, the circuit is readily arranged topermit use of this character.

Now, in Fig. 9, the roller MI is of lesser i111 eter throughout than theguides ill and ll that the current-carrying brush ill is mere" contactwith the current-carryin r ro' The spark clearance is such, however, tlthe predetermined sine ware vo tage is lmpr-e across the gap, the gapwill he jumped o, spark created, with the results previoucl i described. o

It will be understood that the cirl lite, which I have shown, areillustrative, as W3? may he modified to include any or the usualrequirements of a circuit.

The arrangement of the timing, rollers shownis illustrative, as thedevice, especially as shown in Figs. 1 to3, shows one means foraccomplishing certain objects oi! the invention, namely, the control ofa spark gap to have the electrodes so moved with respect to each otherthat an ac curate gap is obtained, the points cleaned automaticaliythrough the movement thereof, and, incidentally, the movement of thepoints serv ing the purpose of an unusually satisfactory timer ifnecessary. Instead of a single cam surface on a roller of this kind, anumber of cam surfaces may be employed, and in adapting the system tovarious conditions, a single or plural number oi rollers may be used, asthe circuit might demand.

Although several embodiments of my invention have been herein shown anddescribed, 1 do not wish to limit myself thereby, but am limited only bythe scope of the appended claims.

What I claim as new and desire to protect by United States lettersPatent is:

1. In an ignition system, a circuit including a source of power and aprimary transformer coil connected by two conductors, a groundedcomnection to one of said conductors, a current changing and sparkingdevice of the character described bridged across said conductors, acondenser in the grounded conductor between the sparking device and theprimary coil, the circuit 2,,0iiiii,237

so arranged to include a primary or cult, and a secondary oscillating cl:u a secondary transformer coil, r one terminal connected to the seconthe other connected to ground, and it com. from the other terminal oi"the secondary coil to the grounded terminal to includes said condenserin the resulting grounded secondary cirr fin oscillatory circuit, acontrol devil circuit including a current carrying roller, oi guards atthe sides thereof electrically in: cd from the roller, a currentcarrying bri gaging the roller and ntities, the roller baring adepressed portion, and means for ti rm roller to periodically place thebrush to ill depressed portion of the roller, the guards sup port thebrush away from the roller o essed portion thereof to form a e tween. 7he device set forth in claim wherein the guides are formed of a hardresisting me trlcally insulated from the current carrylnr i, In anignition circuit, a source of en condenser connected across said source,ti,

1 thereof and or; the roto.

' portion, a ugo.

common to p ,Dl'lil'lfil'. In an ignit quency energy, a 11 its jo marryin denser in "with Lilli prlu said. condenser being also in SEFL'lbcontlnry of said transformer, and control r ill for intermittentlyproviding a variable oi. in a series circuit with saicl primary and.condenser.

6. In an ignition circuit, an oscillatory circuit including a source or"low l'reuuency encrul, to high frequency output transformer, a con" inseries with said source, and prime cl" said transformer, a controldevice for s cult including a roller having periphery w n. circular inpart and spiral in part, a of to brushes adapted upon rotation of rengage the circular periphery there a variable air gap with the spiralof, one ofsaicl brushes being ill in said circuit and other illOlllfi insaid circuit.

I. In an ignition circuit, an oscil atory c r ult frequency outputtransiorrner, a con rice with said source, and the transformer, acontrol device for eluding a roller having a periphery which cular inpart and spiral in part, a pair ol adapted upon rotation of said rollerto em; circular periphery thereof and form variabi a. gap with thespiral periphery thereof, one of sold brushes being included in parallelin said our" it and the other being included in series in saicrl circult, and means for rendering said parallel brush ineffective when thecircuit is in operation. ill

8. In an ignition system, a circuit including a source of current, theprimary windings oi a transformer and a condenser, a primary oscillatingcircuit including a current changing means, the condenser and theprimary winding above set forth, a secondary oscillating circuitincluding a secondary coil, a spark plug, and the same condenserpreviously set forth, said current changing means comprising a currentcarrying roller and current carrying brush with means for separatingthem at proper intervals to produce a spark gap cuit, and a secondaryoscillating circuit including a secondary transformer coil, a spark plugwith one terminal connected to the secondary coil and the otherconnected to ground, and a connection from the other terminal of thesecondary coil to the grounded terminal to include said condenser in theresulting grounded secondary circuit.

10.'In an ignition system, an exciting circuit including a source ofpower, a current changing and sparking device of the characterdescribedconnected by a pair of conductors tothe source of power and a condenserbridged across said conductors, a primary oscillating circuit includingthe primary of a transformer, a spark gap, a condenser, and said currentchanging and sparking device, and a secondary oscillating circuitincluding the secondary of said transformer, a spark plug, said sparkgap and the same condenser included in said primary oscillating circuit.

11. A spark gap for use in an ignition circuit comprising a brushforming one sparking electrode, a moving member having a plane surfacewith a portion of the member forming a second electrode surface, andmeans for supporting the brush by the plane surface of the moving memberin spaced relation to the moving electrode surface;

12. A spark gap for use in an ignition circuit comprising a rotatablemember having a rotatable conducting portion, a second member riding onthe rotatable member, said second member having a conductingportion, andmeans for support ing said second member to ride on the rotatable memberbut with the conducting portion of the second member out of contact withthe conducting portion of the rotatable member, whereby said two membersform a spark gap.

13. A spark gap for an ignition circuit comprising a moving electrodehaving an auxiliary rotation, a stationary electrode, means forsupporting the stationary electrode on the movingsupporting surface ofthe moving electrode to maintain the electrodes in spaced relation, andmeans for varying the spacing between the electrodes during each cycleof rotation,

14. A rotatable spark gap comprising a rotatable member having aperipheral face serving as a moving electrode, and having a peripheralportion acting as a support, a stationary electrode having a portionriding upon said supporting portion of the rotatable member forsupporting the stationary electrode in definite spaced relation to themoving peripheral face serving as a moving electrode.

15. In an ignition circuit, a source of low fre-' quency energy, a highfrequency transformer having its primary in series with said source, a

condenser in series with said primary and source,

said condenser being also in series with the secondary of saidtransformer, and a control device for intermittently providing an airgap in parallel with said primary and condenser and in a series circuittherewith.

r 16. In an igifition circuit, a source 'of low frequency energy, saidsource including high inductance, a high frequency transformer havingits primary in'series with said source, a condenser in series with saidprimary and source, said condenser being also inseries with thesecondary of said transformer, and a control device for in-.,

termittently and alternately providing a short circuit of said sourceand a variable air gap in parallel with said primary and condenser andin a series circuit therewith.

17.-In an ignition circuit, a source of low frequency energy, saidsource including high in ductance, a high frequency transformer havingits primary in series with said source, a condenser in series with saidprimary and source, said condenser belng also in series with thesecondary of said transformer,'and a control device for intermittentlyand alternately providing a short circult of said source and an air gapin parallel with said primary and condenser and in a series circuittherewith.

18. A spark gap comprising a first electrode, a second electrode movablerelative to said first electrode and. slightly spaced therefrom, and insulating means bearing directly on each of said electrodes foraccurately spacing said electrodes apart to form a spark gap betweenthem.-

19. A spark gap comprising a first electrode,

a second electrode movable relative to said first electrode and slightlyspaced therefrom, and an insulating member firmly secured to one of saidelectrodes and bearing on the other of said electrodes for accuratelyspacing said electrodes apart to form a spark gap between them.

20. A spark gap comprising a first electrode unit including an exposedelectrode, a second electrode unit rotatable relative thereto andineluding an electrode exposed toward and slightly spaced from saidelectrode, one of said units hearing on the other of said units, and atleast one of said units including insulating means for accuratelyspacing and alining said electrodes apart to form a spark gap.

21. A spark gap comprising a first electrode unit including an exposedelectrode, a second electrode unit rotatable relative thereto andincluding an electrode exposed toward and slightly spaced from saidelectrode, one of said units hearing on the other or" said units, and atleast one of said units including insulating means for accuratelyspacing said electrodes apart to form a spark gap, said insulating meansfirmly engaging one of said electrodes and engaging the other of saidelectrode units at apolnt adjacent to said a primaryinduction coil and aspark gap in series therewith; means i'or impressing a potential on saidcircuit tending to cause a current to jump said spark gap; and means forreducing the length of said spark gap after the intended sparking timeto insure the passage of current through said coil.

24, In an ignition system, a circuit including a primary induction coiland a spark gap in series therewith; means for impressing a potential onsaid circuit tending to cause a current to Jump said spark gap; andmeans for reducing the length of said spark gap after the intendedsparking time and thereafter closing said gap.

25. An ignition system including a source of power, a primary winding ofa high frequency transformer, and a condenser, all connected byuninterrupted conductors in series in a closed circuit, a spark gapconnected in series with said primary winding and condenser and inparallel with said source of power, and a secondary winding of said highfrequency transformer, and an ignition spark gap connected in a seriescircuit with said condenser.

26.-An ignition system including a source oi power, and a condenserconnected in series by uninterrupted conductors in a closed circuit, aprimary high frequency oscillating circuit in cluding said condenser, aspark gap and a pari mary winding of a highv frequency transform itconnected in series, and a secondary high ,i quency oscillating circuitincluding said con denser, the secondary winding oi said transformer,and an ignition spark gap.

27,. An ignition system including a source oi power and a condenserconnected by unintenrupted conductors in series in a. closed circuit, aprimary high frequency oscillating circuit in eluding said condenser, aspark gap and a pri mary winding of a high frequency transformerconnected in series, a high induction kick circuit for charging saidcondenser with sufilcient p0- tential to Jump said gap, including saidsource of power and a pair of contacts connected in series, and asecondary high frequency oscillating circult including said condenser,the secondary winding of said transformer, and an ignition spark gap.

28. An ignition system for use with internal combustion enginescomprising a plurality of cylinders each having a spark plug, a.distributor for said spark plugs, a circuit including a make and breakdevice, an eiectricsource of supply in series therewith, said circuitincluding an inductance coil series-connected therein, a low tensionwinding of a high frequency transformer and a condenser in series andboth in parallel with said make and break device, and a spark gapforming a current path in parallel with the path of cur-- rentinterrupted by the make and break device.

29.. A spark gap comprising a first electrode, a second electrodemovable relative to said first electrode and slightly spaced therefrom.and a tubular insulating member carrying one of said electrodesinternally thereof and having its open end continually bearing on theother of said electrodes for accurately spacing said electrodes apart toform a spark gap between them.

30. A spark gap comprising a first electrode, a second electrode movablerelative to said first electrode and slightly spaced therefrom, and atubular insulating member carrying one of said electrodes internallythereof and having its open end continually bearing on the other of saidelectrodes for accurately spacing said electrodes apart to form a p kgap between them, and a aocaasr recess in said other electrode in themovement oi said open end thereon, to no air entrapped in saidinsulating mernb r We said electrodes.

31. A combined and spark use in ignition circuits comprising a cutelectrode and an interrupter contact elect connected thereto, and athird member a as both contact and electrode movable relo said sparkingelectrode and contact, engo interrupter contact and slightly spaced f1sparking electrode by an insulating m firmly secured to one oi saidelectrodes and b ing on the other of said electrodes for accurot spacingsaid electrodes apart to form a spark between them, said third electrodehaying proceed portion therein; and means effective said spark gap isthus formed for interrupting engagement of said interrupter electrode byc ing said depressed portion to pass under 20 interrupter electrode toseparate it from .1 third electrode While maintaining said interru torelectrode against movement into the depression formed by said depressedportion.

A combined spark gap and interrupter prising a current carrying rollerhaying dcp oion in its peripheral surfaceon one side th 1 a pair ofguards at the thereof electri iioculatcifi from said roll ucurreut co.

a brush engag...ig the roller, m

guards supporting the brush away from the opposite the depressed portionto intcri current as it passes from contact with ti. and art-parkingbrush concurrently sup the guards at a position accurately once saidroller to form gap therebe 33. In an ignition system, a rotary rialbreak device including a non-rotatahle c1. and a. rotatable contact, oneof which co etc is radially movable and urged toward the other, meansfor rotating said rotatable contact to slide across said fixed contact,support means for supporting said radially movable contact, aid 4,5support means being associated with said 7 sulation and being positionedandshapcc form an air gap and an unobstructed up circuit includingsaid'contacts for on sport: to oscillate thcrebctween.

34. An ignition system for use with intcrrml combustion enginescomprising a circuit in ing in series an inductance coil and a make andbreak device having separating contact areas which are in. engagementlast before ck, means :ior causing current to flow through circuit, acondenser and a low tension Wit of a. high .i'reouericy transformer inseries both connected in a circuit across said i'iontact points, andboth connected in a circuit across electrode areas other than saidseparating cantact areas and forming a spark gap across which thecurrent may ilow independently of said separating contact areas andindependently of said inductance coil.

35. An ignition system for use with. internal combustion enginescomprising a plurality of cylinders each having a spark plug, adistributor for said spark plugs, an electric source of supply, aninductance and a make and break device both in series with said electricsource of supply to form a first circuit; a condenser, a low tensionwinding of a high frequency transformer and conductors connecting saidelements to-\ gether to form second and third circuits, the secondincluding said inductance coil and condenser in series to charge saidcondenser when said make and break device breaks, and the thirdincluding said condenser and low tension winding in series and connectedacross a spark gap formed between electrode areas other than the areasthrough which the current last flows in said make and break device priorto its break, the length of the spark gap formed by said electrode areasbeing adjustable.

36. An oscillatory circuit including a transformer primary coil, acontrol device in said circuit in parallel with said primary coilincluding a current carrying roller, a current carrying brush normallycontacting with the roller, means for turning the roller and meansfor.-moving the roller and brush out of contact with each other toimpede the current and establish a sparking gap between them.

37. An oscillatory circuit including a transformer primary coil, a.control device in said circuit in parallel with said primary coilincluding a current carrying roller, a current carrying brush normallycontacting with the roller, means for turning the roller, the rollerhaving an indented cam surface, and means for preventing the brush fromfollowing the contour-oi such sur-v iace whereby the roller and brushare separated.

and an arcing gap established between them.

38. An oscillatory circuit including a transformer primary coil, acontrol device in said circuit in parallel with said primary coilincluding a current carrying roller, 2. current carrying brush normallycontacting with the roller, means for turning the roller, the camsurface of the roller being so arranged as to predetermine the exactpoint of circuit interruption so that the device may be utilized as atimer.

39. In an ignition system, a rotary make and break device includingfirst and second contacts, one of which is rotatable to slide across theother in contact therewith, and the first of which is movable toward andaway from the second and urged toward it, said second contact having aconducting surface at times engaging the first contact and terminated byan abrupt wall receding from the first contact, and supporting meanssecured to said second contact and having a supporting surface beyondthe plane or" said wall from said contacting surface butinsulated'therefrom; the rotation of said rotatable contact causing arelative motion between said conducting surface and said first contactwhereby said first contact first contacts said surface and then issupported spaced from said second contact by said supporting surface,said supporting surface being so positioned With respect to saidconducting surface as to form an air gap adjacent to it separating saidcontacts as one passes beyond the other to prevent the formation of aconductive film adjacent to said surface and to insure a clean break ofthe current as said make and break device breaks.

HARRY BARNAR-D HOLTHOUSE.

